Table 1.

Surface roughness parameters of the dense PPO and PPO/GO membranes.

Membrane	Surface Parameters
	Ra, nm	Rq, nm
PPO	3.8 ± 0.2	6.6 ± 0.2
PPO/GO (0.1%)	3.3 ± 0.5	5.9 ± 0.5
PPO/GO (0.3%)	3.5 ± 0.5	5.8 ± 0.5
PPO/GO (0.5%)	5.2 ± 0.5	7.2 ± 0.5
PPO/GO (0.7%)	5.5 ± 0.5	7.5 ± 0.5
PPO/GO (0.9%)	5.7 ± 0.5	7.9 ± 0.5